The present invention relates generally to containers and more particularly to a container apparatus including a sandwich structure.
It has long been desired in the box trailer industry to have walls and floors made of lightweight and strong panels which are strongly joined together. Exemplary conventional attempts at such a construction are disclosed in the following United States patents and patent publication: U.S. Pat. No. 7,971,926 entitled “Trailer Having Reduced Weight Wall Construction” which issued to Lemmons on Jul. 5, 2011; U.S. Pat. No. 6,199,939 entitled “Composite Joint Configuration” which issued to Ehrlich on Mar. 13, 2001; and 2013/0224419 entitled “Composite Panel and Joint Construction” which published to Lee et al. on Aug. 29, 2013. All of these are incorporated by reference herein. It is noteworthy, however, that these conventional approaches do not provide sufficient strength to support a trailer floor and/or require difficult and expensive to manufacture panel-to-panel attachments. Furthermore, most traditional devices require additional add-on attachment brackets which span between the adjacent panels; but these configurations typically require juggling of many loose parts while attempting to align and hold the panels in position, along with undesired extra part handling and weight. The localized attachment points also undesirably concentrate the forces during use thereby creating premature panel fractures at the localized points.
U.S. Pat. No. 4,275,663 entitled “Corrugated Vehicle Underframe,” which issued to Sivachenko et al. on Jun. 30, 1981, discloses corrugated sheets between trailer cross-beams and a floor. This patent is incorporated by reference herein. Honeycomb patterns are created between the corrugations. This traditional construction, however, adds significant total thickness when the separate underlying cross-beams are taken into account. Furthermore, some of the corrugated sheets span the entire length of the trailer thereby require forming at the final trailer assembly location which is often impractical.